Wrapping machine



Jan. 29, 1935. E. sMlTHAEr AL WRAPPING MACHINE Filed Aug. 28, 1955 2 Sheets-Sheet l Jan. 29, 1935. E; L. SMITH ET AL WRAPPING MACHINE 2 Sheets-Sheet 2 Filed Aug. 28, 1933 Patented Jan. 29, 1935 UNITED STATES WRAPPING MACHINE Elmer L. Smith, Longmeadow, and Francis Ross Clark, Springfield, Mass., assignors to Package Machinery Company, Springfield, Mass., a corporation of Massachusetts Application August 28, 1933, Serial No. 687,068

5 Claims.

This invention relates to wrapping machines and has particular reference to the improvement of wrapping mechanism of the type in which a partially wrapped article must be forwarded with relation to folding devices with certain unfolded portions of the wrapper trailing behind the article. One form of wrapping machine of this general type is shown in the patents to Armstrong 1,244,277 of October 23, 1917 and 1,308,321 of July 1, 1919, and to Langhammer 1,915,499 of June 27, 1933. In machines of the general type shown in these patents an article is fed along a folding channeL'picks up a sheet of Wrapping material on the way, and then passes folding devices which turn down themarginal portions of the wrapper on the sides of the article so that the wrapper temporarily assumes the form of a tube having an open ended extension projecting behind the article. The speed of operation of machines of this character has previously been restricted on account of the long stroke necessary for a single plunger to carry the article completely through the folding channel. Step by step transporting mechanism which has been used in other types of wrapping machines in order to reduce the forward motion of the article at each cycle and therefore speed up the machine by operating upon several articles simultaneously has not been applicable to machines of the type under discussion for the reason that the rearwardly projecting tubular extension of the wrapper interferes with the operation of the transporting mechanism. Contrary to what has been the common practice in the design of machines of this type we have now found that by properly designing the transport mechanism it can be adapted to machines in which the wrapper has during a portion of its formation a rearwardly extending tubular portion.

'Ihe invention will now be described in connection with a preferred embodiment shown in the accompanying drawings in which:

Fig. 1 is a side elevation partly in median section of a portion of a wrapping machine embodying the invention;

Fig, 2 is a detail of the transport mechanism illustrating the path given to the'transporter fingers;

Fig. 3 is a detail corresponding to a portion of Fig. 1 but showing a diierent position of the parts;

Fig. 4 is a top view, and

Fig. 5 is a side view showing the condition of the article and wrapper just prior to the Contact therewith of the first ltransporter fingers;

Figs. 6 and 7 are similar views showing the transporter fingers in full contact;

Fig. 8 is a diagrammatic side view showing two stages in the folding of the wrapper with the transporter fingers in contact;

Fig. 9 is a similar view showing the condition of the wrapper after its release by the transporter fingers;

Fig. 10 is a diagrammatic side View of the final wrapping position; and

Fig. 11 is a rear view of the'final wrapping position.

Ihe machine is supported upon a frame 11 bearing aligned plates 12 and 13 forming the bottom of a folding channel. A hopper 14 is supported upon the frame to the rear of the plate 12 to supply to the machine a succession of articles indicated at a in the drawings. The initial forwarding of the articles is accomplished by a double elevation plunger 15 of the general type shown in the second Armstrong patent referred to. This plunger has an upper article contacting face 16 and a lower extension 17 operating successively on the articles ina manner which will be described. The plunger is mounted upon a slideway 18 and is guided between parallel bars 19 fixed to the frame. A lever 20 is pivoted at 21 to the frame and is joined to the plunger 15 by a short connecting link 22. A link 23 joins the lower end of the` lever 20 to an eccentric 24 on a cam shaft 25. As this cam shaft rotates the plunger will be given a reciprocation toward the left as viewed in Fig. l, this reciprocation however being less in extent than in the second Armstrong patent cited above. The reduction in the stroke of the plunger renders it possible to operate the machine at higher speeds since instead of forcing a single'article all the way through the folding channel by one motion of the plunger several articles are in the process of being forwarded at the same time by the mechanism to be described below.

Initially in the position shown in Fig. 1 the lowermost article in the hopper is resting upon the extension 17 in front of the plunger face 16. As the plunger moves forward this lowermost article will be carried with it underneath a pivoted hold down plate 26. When the plunger returns, so that the end of the extension 17 retires behind the article, this article will be forced down against the plate 12 by the hold down plate. Latches 27 are preferably provided to prevent retrograde movement of the article and the article is guided by side plates 28. After one complete Ieciprocation of the plunger the first article will be left in the position a' shown in Fig. 1.

Between the plates 12 and 13 a sheet s of wrapping material is positioned by guides 30 and a stop 31 so that it extends across the path of motion of the article. Just beyond this sheet are mounted the usual side tuckers 32 at the edge of a folding channel formed between plate 13 and an upper plate 33 held down yieldingly as by a spring plunger 34. The article is moved into the position a by the plunger extension 17, this position being indicated both in Fig. 1 and in Figs. 4 and 5.

Movable in a slot formed in the center of the plate 13 is a transporter bar 40 having in the case shown two article forwarding fingers 41 and 42. The transporter bar is mounted on a pair of links 43 and 44 pivoted at 45 and 46 respectively to one arm of each of a pair of bell cranks 47 and 48 mounted upon stub shafts 49 and 50. The second ends of the two bell cranks are connected together by a link 5l. Vertical motion of the transporter bar by which the ngers are projected into and out of the wrapping channel is accomplished by a. cam on the cam shaft 25 coupled with the shaft 45 through a link 53. Horizontal movement of the transporter bar, by which the fingers are moved along the channel is accomplished in synchronism with the movement of the plunger 15, a link 54 connecting the arm 44 with the arm 20. The sides of the folding channel are provided with opposed stationary folders 55 and 56 and also with opposed wheels 57 (only one being shown in the drawings) for applying a suitable sealing liquid to the Wrapping material. The manner in which the sealing liquid is applied is preferably the same as in the Langhammer patent referred to and need not be described in detail. At the end of the folding channel are opposed side tuckers 58 preferably similar to the tuckers 82 of the Langhammer patent and carrying the sealing liquid to the aps in the same manner, a bottom tucker 59 and a sealing liquid applying device 60 all similar in construction to corresponding parts in the Langhammer patent. At this same stage is also mounted a plunger 61 which serves to elevate the article into a receiving chute 62 by which the last fold is made.

Considering the start of the folding operation with an article in the position a the plunger face 17 advances and forces; the article through the sheet of wrapping material into the folding channel. By this means the wrapper is brought into contact with the leading end and the top and bottom of the article and at the same time side tucks c are formed by the tuckers 32. The article is deposited by the plunger face 17 in the position a" in which the flaps d are in the process of being folded upwardly against the article end by the, stationary folders 55. At the start of the next cycle of operation the transporter ngers 41 rise along the path indicated at b in Fig. 2 so as to come in contact with the rear of the article. In doing this the nger 41 strikes the lower rearward extension of the wrapper and makes a temporary fold shown at f in Figs. 6 and 7. "I'he article is not at this point ready to have the final fold made, and in accordance with the present invention the transporting finger is so designed that the fold f'will not be permanent in character. To this end the transporter finger is made much narrower than the article as clearly shown in Fig. 6 in order to avoid making any crease adjacent the corner between this ilap and the flap d preferably turned up. With strongly resilient materials such as cellophane this alone may be sufficient to prevent giving the temporary flap f any permanent set. With less resilient wrapping materials it may be desirable to cut away the transporter finger as indicated in dotted lines 65 and 66 in Fig. 2 so that no pressure is brought to bear against the lower rear corner of the article.

After the initial engagement of the finger 41 with the article as shown in Fig. 7 the transporter moves forwardly along the horizontal position of its path carrying the article to the position a". In its passage to this position the article passes the sealing liquid applying device 57 and approaches the folders 56 which operate to turn down the upper flaps e. As the transporter moves rearwardly along the lower portion of the path shown in Fig. 2 the flap f is released and springs back to its normal horizontal position. The next succeeding advance of the transporter causes engagement of the nger 42 with the article and again turns up the temporary flap f. As the finger 42 advances the article is carried on to the elevating plunger 61 in position to have the rearwardly extending wrapper portions engaged successively by the side tuckers 58, the folder 59 and the dauber 60. The operation of these parts is clearly shown in'Figs. 21 and 23 of the Langhammer patent and need not be repeated here. It will be clear, however, that the nger 42 has released the ap 41 as indicated in Fig. 9, and thus has permitted the return of this flap to its normal horizontal position before the tuckers 58 act upon the article. The tuckers 58 are preferably slanted as shown in Fig. 11 so that their upper portions contact first. If there is any partial set of the lower flaps f as indicated in this figure, that flap will be forced back into position and the side tucks g formed rst by the tuckers 58 before the folder 59'acts on the flap f. The nal fold a' is given in the customary way by elevating the article into the folding chute 62.

The mechanism has been described in considerable detail in order to make clear the construction and operation of the preferred form of device. It will be understood however that changes in the described apparatus may be made in adapting it to other forms of wrapping machines within the scope of the invention as dened in the appended claims.

We claim:

1. A wrapping machine comprising a wrapping channel, means for supportinga sheet of wrapping material in position across the channel so that when an article is fed along the channel the wrapping material will be folded across the leading side and two adjacent opposed sides of the article leaving portions of the wrapper trailing behind the article, folders in the channel positioned to fold down the side portions of the wrapper and form the same into a tube having an open end trailing behind the article, mechanism for forwarding an article along the channel including a parallel motion transporter having one or more fingers adapted to engage one side of the open end of the wrapper tube and fold it against the article, and then to move the article along the channel, each transporter nger being narrower than 'the width of the rear of the article so that the fold made will not be permanent and will spring back substantially to its original position when the nger disengages the rear of the article the tubular extension at the rear of the article.

2. A wrapping machine comprising a Wrapping channel, means for supporting a sheet of wrapping material in position across the channel so that when an article is fed along the channel the wrapping material will be folded across the leading side and two adjacent opposed sides of the article leaving portions of the wrapper trailing behind the article, folders in the channel positioned to fold down the side portions of the Wrapper and form the same into a tube having an open end trailing behind the article, mechanism for forwarding an article along the channel including a parallel motion transporter having one or more fingers adapted to engage one side of the open end of the wrapper tube and fold it against the article, and then to move 'the article along the channel, each transporter finger being narrower than the width of the rear of the article so that the fold made will not be permanent and will spring back substantially to 'itsoriginal position when the finger disengages the article, and folders operative to fold against the rear of the article the tubular extension at the rear of the article, said last named folders operated to fold first against the article a flap other than the one temporarily folded by the transporter fingers.

3. A wrapping machine comprising a wrapping channel, means for supporting a sheet of wrapping material in position across the channel so that when an article is fed along the channel the wrapping material will be folded across the leading side and two adjacent opposed sides of the article leaving portions of the wrapper trailing behind the article, folders in the channel positioned to fold down the side portions of the wrapper and form the same into a tube having an open end trailing behind the article, mechanism for forwarding an article along the channel including a parallel motion transporter having one or more ngers adapted to engage one side of the open end of the wrapper tube and fold it against the article, and then to move the article along the channel, each transporter linger being narrower than the width of the rear of the article and being shaped to avoid contact with the edges of the article so that the fold made will not be permanent and will spring back substantially to its original position when the finger disengages the article, and folders operative to fold against the rear of the article the tubular extension at the rear of the article, said last named folders operated to fold first against the article a ap other than the one temporarily folded by the transporter fingers.

4. A wrapping machine comprising folding devices, and means for forwarding a partially Wrapped article relative to said folding devices including a nger engaging and' temporarily folding an outstanding portion of the wrapper, said iinger being so shaped as to avoid creasing the flap whereby the latter will spring back to substantially its original position when released by the finger, and said folding devices including a folder for folding against the article the wrapper portion temporarily folded by the nger.

5. A wrapping machine comprising folding devices, and means for forwarding a partially wrapped article relative to said folding devices including a nger engaging and temporarily folding an outstanding portion of the wrapper, said finger being so shaped as to avoid creasing the flap whereby the latter will spring back to substantially its original position when released by the finger, and said folding devices including a folder for folding against the article the wrapper portion temporarily folded by the nger only after other adjacent portions of the wrapper have been folded.

ELMER L. SMITH. FRANCIS ROSS CLARK. 

